The invention relates to a micro switch and, more particularly, to a micro switch having bi-directional operation to switch on/off the electrical contact point.
A conventional small-sized micro switch with bi-directional operation for switching on/off the electrical contact point utilizes terminals that have first and second conductive portions protruding from the sidewall opposite to the acceptance room. When in a free state, the first conductive portion is not in contact with the first movable contact portion of the coil spring. Conversely, when the switch is activated, the operation portion of pushbutton will be pressed down, which in turn will cause the coil spring to move, making a contact with the first movable contact portion. Unlike the first conductive portion, the second conductive portion often contacts the second movable contact portion of coil spring. Therefore, in order to prevent the pushbutton from shifting or detaching caused by pushing-up resilience generated by the coil spring when the pushbutton is trying to get back to its original free state after a switching on/off action, the pushbutton has to contain a first brake element that is extending from the location of pivot point axis so that the pushbutton can perform positioning for itself at the location where the pivot point axis departs. On the other hand, the main body of micro switch has a second brake element formed at the main body thereon. The second brake element will touch the first brake element of pushbutton when the first brake element receives force from the coil spring and begins to rotate relative to the shut direction. After that, positioning a free-state pushbutton can then be performed.
However, regarding to the above-mentioned positioning method, since the volume of micro switch is very small, it is not an ideal method to form another tiny brake element because the brake element cannot provide good strength, neither can it be manufactured with good degree of precision. Therefore, the yielding of product will not be good enough if the method is applied, and the cost of assembling labor will also increase since product precision control cannot be well performed, either.
Moreover, if product precision is not good enough, or if the coil spring becomes fatigued because the downward-pressing process is too long, the often-in-contact manner between the second conductive portion and the second movable contact portion of the coil spring will then fail to be kept. Consequently, the switching-on-for-conducting made by the electrical contact point cannot be generated when the pushbutton is pressed down; that is, the small-sized switch has lost its function of conducting-at-pressing. In other words, the lifespan of micro switch is shortened.
To solve the above problems, the object of the invention is to provide a micro switch that is easy to be assembled and manufactured without taking the trouble to change volume for the existing product as well as to go through complicated manufacturing process and product precision control. Through a conjoining portion formed between a first conductive portion and a second conductive portion of resilient element that are used for switching on/off the electrical contact point, and through a positioning portion that is for conjoining to the resilient element and is provided in the concave slot of the pushbutton corresponding to the conjoining portion, the first conductive portion of resilient element can then often keep in a contact manner with the first contact portion of first conductive terminal extending to the acceptance room. In addition, the second conductive portion can move downwards to contact the second contact portion of second conductive terminal extending to the acceptance room because the second conductive portion is pressed by a pressing portion provided corresponding to the pushbutton. Therefore, a micro switch easy to be assembled is formed.